Facer for End Fusion of Polyolefin Pipes

ABSTRACT

A facer facing the ends of polyolefin pipes for butt fusion is modular in the sense that it employs three types of modules, a drive unit, two blade holders and a motor assembly, that are separable from one another and each independently light enough to be hand-lifted along walls and up to ceilings. The drive unit module is adjustable to accommodate different guide rail spacings. The blade holder modules are interchangeable to accommodate different diameters of pipe. The motor assembly module has multispeed capability to accommodate the total area of material to be faced. Each module can be exchanged or modified without use of tools to change the geometry of the assembled facer to accommodate different fusion machines and/or diameters of pipe within working spaces dictated by the diameter of the pipe and not by a fixed geometry of a facer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. Provisional patent applicationSer. No. 15/709,468 titled “FACER FOR END FUSION OF POLYOLEFIN PIPES,”filed Sep. 19,2017, the contents of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

This invention relates generally to machines used in the process offusing polyolefin pipe and more particularly concerns facers used toprepare the opposed ends of two polyolefin pipes for butt fusion.

Situations in which a facer might be of use in extending a polyolefinpipe in a tight working space, such as adjacent a wall or ceiling, arenot uncommon. And accessibility to such a tight working space may befurther complicated by the presence of other pipes, equipment andsupporting structure in the vicinity. Unfortunately, however, knownfacers for polyolefin pipes of mid-range diameter are poorly designedfor such applications.

Most known mid-range diameter polyolefin pipe facers are simply tooheavy to be lifted by hand into such tight working spaces. For example,facers for 24″OD polyolefin pipe typically weigh between 200 and 400pounds.

Many facers are designed to face a range of pipe sizes and so theiroutput speeds (RPM) are selected to handle the largest diameter orthickest wall pipe in their pipe range. Consequently, when they are usedto face a pipe with a smaller diameter or thinner wail, they operateslower than necessary and do not make full use of their availablehorsepower.

Most known facers are designed to be mounted on carriages of only onesize and their carriages are designed to be modified to permit the samefacer to face a range of pipe sizes. Such facers must be sized for thelargest pipe diameter in their range. Consequently, when used to faceruns of smaller diameter pipe, the carriage size prevents the runs ofpipe from being as close together as might otherwise be possible.

And most known facers produce polyolefin ribbons that can wrap tightlyaround the ends of the opposed pipes during facer rotation. The ribbonscan block the operator's view of the pipe ends and can build upsufficiently to require periodic stoppage of the facing process to clearthe ribbons. Furthermore, the ribbons can fall into, tangle in and behard to clean out of the fusion machine.

It is, therefore, an object of this invention to provide a polyolefinpipe facer that is of use in extending a polyolefin pipe in a tightworking space. Another object of this invention is to provide apolyolefin pipe facer that reduces the impact of a facer's weight on itsutility for use in a tight working space. A further object of thisinvention is to provide a polyolefin pipe facer that reduces the impactof a facer's size on its utility for use in a tight working space. It isalso an object of this invention to provide a polyolefin pipe facer thataffords greater accessibility to tight working spaces than known facers.Yet another object of this invention is to provide a polyolefin pipefacer that makes full use of its available horsepower for more than onesize of pipe. An additional object of this invention is to provide apolyolefin pipe facer that enables the running of multiple sizes of pipecloser together than is possible with known facers. And it is an objectof this invention to provide a polyolefin pipe facer that controls thedispersion of polyolefin ribbons produced by the facer.

SUMMARY OF THE INVENTION

In accordance with the invention, a facer is provided that can bemounted on the guide rails of a fusion machine carriage and used toprepare polyolefin pipes for end fusion.

The facer has a drive unit with guide rail brackets and an output shaft.The brackets are adapted for tool-free engagement preventing horizontaland vertical displacement of the drive unit relative to the guide rails.Two blade holders are adapted for tool-free engagement on and rotationwith the output shaft of the drive unit with the blade holders inparallel and on opposite sides of the drive unit. A motor assembly isadapted for tool-free engagement preventing horizontal and verticaldisplacement of the motor assembly in relation to the drive unit. Alinkage engages the output shafts of the drive uni: and the motorassembly for transmission of power from the motor assembly output shaftto a drive unit output shaft. The linkage may be a mechanical couplingand may include a gearbox.

The facer drive unit has a horizontal output shaft parallel to the guiderails. The free ends of the horizontal output shaft are on oppositesides of the drive unit and have penultimate portions of identicalnon-circular cross-section and ultimate portions with identicalconcentric circular adapters. Each blade holder has a center openingcomplementing the penultimate portion of a respective free end of thehorizontal output shaft. Two latching assemblies, each surrounding itsrespective blade holder center opening, are operable to secure theirrespective blade holder to a respective one of the shaft concentriccircular adapters with the center opening engaged on its respectiveshaft penultimate portion and with the two blade holders in parallelrelationship. Preferably, each non-circular free end of the horizontaloutput shaft is hexagonal and each latching assembly is a split wedgeclamp ring. The facer may have multiple pairs of blade holders ofdifferent diameters interchangeable with two blade holders. At least oneblade is mounted on each blade holder at an angle selectable to causeribbons of polyolefin shaved thereby to be dispensed either inside of oroutside of their respective pipe.

The drive unit module of die facer has an elongated frame and two guiderail brackets, one on each end portion of the frame. Two arrays ofco-operable registries, each array corresponding to a respective one ofthe guide rail brackets, are configured to locate the guide railbrackets in any of multiple symmetrically spaced relationships from acenter of the frame. Two indexing assemblies, one on each end portion ofthe frame, configured to secure the guide rail brackets in any ofmultiple symmetrically spaced relationships, are used to space the guiderail brackets in the spaced relationship closest to the distance betweenthe guide rails. The guide rail brackets are U-shaped. A horizontalU-shaped bracket is engageable on one of the guide rails by lateralmotion of the frame. A vertical U-shaped bracket is engageable on theother guide rail by downward motion of the vertical U-shaped bracketwith the horizontal U-shaped bracket engaged on the one of the guiderails. A clamp mounted on the horizontal U-shaped bracket constrainsfacer motion in a vertical plane. A clamp mounted on the verticalU-shaped bracket constrains facer motion in a horizontal plane. A latchassembly mounted on the vertical U-shaped bracket retains the facer onthe guide rails. Each array of co-operable registries has multipleapertures spaced longitudinally on the elongated frame and an apertureon its respective one of the guide rail brackets. Each index assembly isa spring pin. The linkage has an input shaft, an output shaft and agearbox between the input and output shafts. Two adapters, one on eachend of the linkage output shaft, enable tool-free engagement on androtation with the linkage output shaft of a respective blade holder withthe blade holders in parallel. A mounting socket is adapted forengagement with the frame of the drive motor assembly.

Each blade holder module has a disk with a center opening for closelyfitting a perimeter of a penultimate portion of the end of the driveunit module output shaft. A latching assembly surrounds the centeropening and is operable to secure the disk to an ultimate portion of theend of the drive unit module output shaft with a disk perpendicular tothe shaft. A blade is mounted on a distal face of the disk relative tothe output shaft of the drive unit at either an angle causing ribbons ofpolyolefin shaved thereby to be dispensed inside of the pipe or an anglecausing ribbons of polyolefin shaved thereby to be dispensed outside ofthe pipe. The disk has a recess in its distal face with two pairs of twoholes in the recess registrable with two holes in the blade. Alignmentof the two holes in the blade with one of the two pairs of holes in thedisk causes the blade to be at the angle causing ribbons of polyolefinshaved thereby to be dispensed inside of the pipe. Alignment of the twoholes in the blade with the of the two pairs of holes in the disk causesthe blade to be at the angle causing ribbons of polyolefin shavedthereby to be dispensed outside of the pipe. The center opening isnon-circular and preferably hexagonal. The latching assembly ispreferably a split wedge clamp ring.

The motor assembly module has a motor, a gearbox driven by the motor, anoutput shaft from the gearbox and a coupler on a free end of the outputshaft. A connector has plug-and-socket components, one fixed to themotor assembly module and the other fixed to the frame of the drive unitmodule. The components have a configuration adapted for tool-freeengagement preventing horizontal and vertical displacement of the motorassembly module in relation to drive unit module with the gearbox outputshaft coupler engaged with the input shaft coupler for rotation with thegearbox output shaft. In this configuration, the couplers are spacedfrom their respective components so as to align the couplers on a commoncenter axis of the drive unit input shaft and the gearbox output shaft.One component of the connector is adapted to telescope in the othercomponent to engage the couplers. Apertures in the telescopingcomponents are alignable to cooperate with a detent pin to secure themwith the couplers engaged. The telescoping components are preferablyvertically aligned tubular members of square cross-section. The gearboxis preferably a multi-speed gearbox operable at a speed selected tocorrespond to a cross-section of a pipe being faced.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of tic invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIG. 1 is a perspective view of a preferred embodiment of a facer inaccordance with the invention for use in a process for end fusion ofpolyolefin pipe;

FIG. 2A is an enlarged perspective view of a preferred embodiment of thedrive unit of the facer of FIG. 1;

FIG. 2B is a top plan view illustrating a preferred embodiment of thegear assembly housed in the gearbox of the drive unit of FIG. 2A:

FIG. 2C is a bottom plan view of the gear assembly of FIG. 2B;

FIG. 2D is an elevation view of the gear assembly of FIG. 2B as seen inthe direction D-D of FIG. 2A;

FIG. 2E is an elevation view of the gear assembly of FIG. 2B as seen inthe direction E-E of FIG. 2A;

FIG. 2F is an elevation view of the gear assembly of FIG. 2B as seen inthe direction F-F of FIG. 2 A;

FIG. 3A is an enlarged perspective view illustrating one cutting face ofa preferred embodiment of the two blade holders of the facer of FIG. 1with its blades in a “ribbon-inside” configuration;

FIG. 3B is an enlarged perspective view illustrating the other cuttingface of the preferred embodiment of the two blade holders of the facerof FIG. 1 with its blades in a “ribbon-outside” configuration;

FIG. 3C is an enlarged perspective view illustrating one cutting face ofa preferred embodiment of the two blade holders of the facer of FIG. 1with its blades in a “ribbon-inside” configuration;

FIG. 3D is an enlarged perspective view illustrating the other cuttingface of the preferred embodiment of the two blade holders of the facerof FIG. 1 with its blades in a “ribbon-outside” configuration;

FIGS. 3E, 3F and 3G are perspective views illustrating large, medium andsmall blade holders, respectively, for use with the same drive unitaccording to FIG. 2A;

FIG. 4 is a perspective view of a preferred embodiment of the motorassembly of the facer of FIG. 1;

FIG. 5 is a perspective view of the three modules of the facer of FIG. 1arranged for assembly into a facer according to FIG. 1;

FIG. 6 is a perspective view of the drive unit seen in FIG. 5 aftermounting on the guide rails of a fusion machine carriage;

FIG. 7 is a perspective view of the blade holders seen in FIG. 5 aftermounting on the drive unit which is on the guide rails as seen in FIG.6;

FIG. 8 is a perspective view of the motor assembly seen in FIG. 5 aftermounting on the drive unit with the blade holders as seen in FIG. 7; and

FIGS. 9A and 9B are side elevation views illustrating the assembledfacer of FIG. 8 using the large and small blade holders of FIGS. 3E and3G, respectively.

While the invention will be described in connection with preferredembodiments thereof, it will be understood that it is not intended tolimit the invention to those embodiments or to the details of theconstruction or arrangement of parts illustrated in the accompanyingdrawings.

DETAILED DESCRIPTION The Facer

Looking first at FIG. 1, a modular facer F is adapted to be engaged onthe guide rails R (seen in FIGS. 6-8) of a fusion machine carriage (notshown) for the purpose of facing the ends of polyolefin pipes P (seen inFIGS. 9A-9B) for butt fusion. The term “polyolefin” identifies a mostcommon application of the modular facer but is intended to include“nylon,” PVC and other fusible non-polyolefin pipes.

The facer F is modular in the sense that it employs three types ofmodules including a drive unit 10, two blade holders 60 and a motorassembly 80 that are separable from one another. Each module 10, 60, 80is independently light enough to be hand-lifted along walls and up toceilings (not shown). However, the modules 10, 60 and 80 can each beexchanged or modified without use of tools in order to change thegeometry of the facer F so that the same facer F can be used to facedifferent diameters of pipe within working spaces dictated by thediameter of the pipe and not by the fixed geometry of a fusion machineand facer.

This is made possible by use of a drive unit 10, seen in FIGS. 1 and2A-2F, that is adjustable to accommodate different spacing between guiderails R of different fusion machines, by use of blade holders 60, seenin FIGS. 1 and 3A-3G, that are interchangeable to accommodate differentdiameters of pipe P and by use of a motor assembly 80, seen in FIGS. 1and 4, that has multispeed capability to accommodate the total area ofmaterial to be faced, a total which varies in relation to the diameterand thickness of the pipe.

The Drive Unit

Turning to FIG. 2A, a preferred embodiment of the drive unit 10 of thefacer F is seen mounted on the guide rails R of a carriage of a machineused to fuse polyolefin pipe end-to-end. An elongated frame 11 has twoguide rail brackets 12 and 13, one on each end portion of the frame 11.Two sets of registries 14 and 15, each corresponding to a respectiveguide rail bracket 12 or 13, are configured to locate their respectivebrackets 12 or 13 in any of multiple symmetrically spaced relationshipsfrom a center axis 21 of the elongated frame 11. Looking at FIG. 2A inthe direction D-D, the left hand registries 14 and 15 are not seen butare a mirror image of the right hand registries 14 and 15. Two indexingassemblies 16, one on each end portion of the elongated frame 11, securetheir respective brackets 12 or 13 in any selected one of multiplesymmetrically spaced relationships at the spaced relationship that isclosest to the distance between the guide rails R. Thus, a single driveunit frame 11 can, for example, fit six different sizes of fusionmachine carriages if the locations of the guide rail brackets 12 and 13have registries 14 that are adjustable to six different carriage guiderail spacings.

The elongated frame 11 as illustrated is fixed in overall length. Theguide rail brackets 12 and 13 slide inward for smaller fusion machinecarriages but the frame overall length of the frame 11 stays the same.However, the frame 11 may be retractable within the space between theguide rail brackets 12 and 13, for example by use of a telescoping frameor exchangeable frame arms.

As seen in FIG. 2A, both guide rail brackets 12 and 13 are U-shaped withone being horizontal 12 and the other vertical 13. The horizontalbracket 12 is engageable on its respective guide rail R by lateralmotion of the elongated frame 11 and the vertical bracket 13 isengageable on its respective guide rail R by downward motion of itsrespective end of the elongated frame 11 with the horizontal bracket 12engaged on its respective guide rail R.

Also as shown in FIG. 2A, each set of registries 14 and 15 includesmultiple apertures 14 spaced longitudinally on the elongated frame 11and an aperture 15 on its respective guide rail bracket 12 or 13. Eachindex assembly 16 is a spring pin that, when its respective bracketaperture 15 is aligned with a selected one of its respective multipleapertures 14 on the elongated frame 11, can be engaged in its respectivealigned apertures 14 and 15 to secure the brackets 12 and 13 atsymmetrical spacing from the center axis 21 of the elongated frame 11.

After the horizontal guide rail bracket 12 is registered and indexed onthe frame 11, a clamp 17 mounted on the bracket 12 is tightened by useof a knob 18 to constrain facer motion in a vertical plane. After thevertical guide rail bracket 13 is registered and indexed on the frame11, a clamp (not seen) mounted on the bracket 13 is tightened by use ofa knob to constrain facer motion in a horizontal plane. The verticalbracket clamp is similar to the horizontal bracket clamp 17 but in a 90°rotated orientation.

A latch assembly 19 mounted on the vertical guide rail bracket 13retains the facer F on the guide rails R. As best seen in FIGS. 9A and9B, the latch assembly 19 has a latch arm that pivots to cross under theguide rail R and engage a latch slot on the other side. A pull springpin secures the arm in the latched or unlatched position. The horizontalguide rail bracket 12 cannot slide off its guide rail R as long as thevertical guide rail bracket 13 is on its guide rail R.

In the embodiment of FIG. 2A, a mounting socket 22 on the elongatedframe 11, as shown fixed on the top of the frame 11 in alignment withthe center axis 21, is adapted for engagement with the frame 85 of themotor assembly 80, hereinafter discussed. And each of the guide railbrackets 12 and 13 is equipped with a handle 23 to facilitate liftingand manipulating the drive unit 10 into position on the guide rails R.

Also, as shown in FIG. 2A, the drive unit 10 has a linkage 24 with aninput shaft 25 and an output shaft 26. Two adapters 27 and 28, one oneach end of the linkage output shaft 26, enable tool-free engagement androtation of respective blade holders 60 on and with the linkage outputshaft 26 with the blade holders 60 in parallel. Preferably, the linkage24 includes a hypoid gear 29 that converts input shaft 25 rotation abouta vertical axis to output shaft 26 rotation about a horizontal axis.This enables the motor assembly 80 to be centered and balanced, ratherthan cantilevered and imbalanced, on the input drive 10.

Looking at FIGS. 1 and 2A, a preferred embodiment of the drive unitlinkage 24 extends from its input coupler 31 through a gearbox 32 to theadapters 27 on its output shaft 26. As seen in FIGS. 2B-2F, the linkage24 is illustrated with the housing of the gearbox 32 removed. Thelinkage input shaft 25 rotates on ball bearings 33 in unison with theinput coupler 31 on one of its ends and a drive sprocket 34 on its otherend. The input coupler 31 is adapted to mate with an output shaftcoupler 84 of the motor assembly 80 to transfer torque via the inputshaft 25 to the drive sprocket 34. The drive sprocket 34 is engaged by aroller chain 35 to a driven sprocket 36 with its sprocket shaft 37mounted on tapered roller bearings 38. In this embodiment, the “sprocketshaft” 37 is an extension of the pinion 39 and extends in parallel withthe drive unit input shaft 25 to a pinion 39 engaged with a ring gear41. The ring gear 41 and pinion 39 redirect the rotational motion of theinput and drive sprocket shafts 25 and 37 about their vertical axes tothe rotational motion of the output shaft 26 of the drive unit 10 aboutits horizontal axis.

Continuing to look at FIGS. 2B-2F, the output shaft 26 of the drive unit10 extends at each end to respective adapters 27 and 28 configured fortool free connection to a respective blade holder 60. As shown, theblade holder adapters 27 have identical penultimate noncircular portions42 and identical ultimate concentrically circular portions 43 cooperablefor mating with components of its respective blade holder 60 hereinafterdescribed. As shown, die penultimate noncircular portion 42 of theadapters 27 are hex shaped.

The Blade Holder

Looking now at FIGS. 1 and 5, two blade holders 60 are mounted on thedrive unit 10 with the blade holders 60 parallel to each other and onopposite sides of drive unit 10. As shown, each blade holder 60 is adisk 61 with a center opening 62 for closely fitting a perimeter of anend of the facer output shaft 26. Each blade holder 60 has a latchingassembly 63 operable to secure the disk 61 to an end of the facer outputshaft 26.

Turning to FIGS. 3A-3B, each blade holder 60 is preferably a circulardisk 61 with a center opening 62 complementing its respectivepenultimate noncircular portion 42 of the horizontal output shaft 26 ofthe drive unit 10. Each blade holder latching assembly 63 surrounds itscenter opening 62. The latching assembly 63 is operated to secure itsblade holder 60 to the drive unit output shaft 26 after the centeropening 62 of the blade holder 60 has been fully engaged on thepenultimate noncircular portion 42 of the drive unit output shaft 26.Preferably, and as seen in FIGS. 3A-3B, the latching assembly 63 is asplit wedge clamp ring adapted to grip the ultimate concentricallycircular portion 43 of the drive unit output shaft 26 that will extendthrough the latching assembly 63 when the blade holder 60 is fullyengaged on the penultimate noncircular portion 42 of the drive unitoutput shaft 26. As shown, the noncircular portions 42 of the drive unitoutput shaft 26 and the center openings 62 of the blade holder disk 61are hexagonal.

Now looking at FIGS. 3C-3D, each blade holder 60 has at least one blade64 mounted on an outside face of the disk 61. If, as seen in FIG. 3C,the shaving edge 65 of the blade 64 is at an angle 66 in which itsdistal end leads its travel, shaved ribbons S of polyolefin will bedispensed inside of the pipe P being shaved. If, as seen in FIG. 3D, theshaving edge 65 of the blade 64 is at an angle 67 in which its distalend trails its travel, shaved ribbons S of polyolefin will be dispensedoutside of the pipe P being shaved.

As best seen in FIGS. 3C-3D, a blade 64 is mounted in a V shaped recess68 in the outer face of the disk 61. The recess 68 has two sets 69 and71 of at least two holes, as shown two sets of three holes, which areregistrable with at least two holes in the blade 64. The alignment ofthe blade holes with one set 69 of recess holes orients the blade 64 atthe angle 66, causing shaved ribbons S of polyolefin to be dispensedinside of the pipe P. The alignment of the blade holes with the otherset 71 of recess holes orients the blade 64 at the angle 67, causingshaved ribbons S of polyolefin to be dispensed outside of the pipe P. Asshown, the blade 64 is secured in the recess 68 using screws 72.Multiple blades 64 can be mounted on a disk 61, preferably at equalangular displacements on die disk 61, with each blade 64 in a separaterecess 68.

The two blade holders 60 are mirror images to provide proper orientationof the blades and position in their V shaped recesses 68. Each bladeholder 60 is mounted on its respective side of the facer F so that whenrotating the blade edge 65 is leading and cutting and not trailing anddragging with the blade 64 on the trailing side of the V-shaped recess68.

For normal operation, the blade 64 is oriented to disperse the shavedribbons S inside the pipe P, as seen in FIG. 3C. They remain inside thepipe P during the entire facing operation. As a result, the ribbons S donot tangle in the facer F or the fusion machine and do not wrap tightlyaround the pipe P. Therefore, it is not necessary to periodically stopfacing to clear the shaved ribbons S. Furthermore, ribbons S do not wraparound the pipe P, so the operator's view of the pipe periphery is notblocked. After facing, cleanup is easily accomplished by pulling abundle of ribbons S from each pipe end.

For fusion of vertically oriented pipe P, the blade 64 is positioned asseen in FIG. 3D so ribbons S drop outside of the pipe P and down and donot tangle in the facer F. Also, for fusion of vertically oriented pipeP, the blade 64 on the lower blade holder 60 can be angled to disperseshaved ribbons S outside of its respective pipe P and the blade 64 onthe upper blade holder can be angled to disperse shaved ribbons S insideof its respective pipe P.

Moving on to FIGS. 3E-3G, for the same drive unit 10, pairs of bladeholders 60 of one diameter are interchangeable on the output shaftadapters 27 and 28 with pairs of blade holders 60 of another diameter.For example, blade holders 60 of large, intermediate and small outerdiameter 73,74 and 75, shown in Figures 3E, 3F and 3G, respectively, butall have the same size center openings 62 and latching assemblies 63.Furthermore, the lengths of the blades 64 can be sufficient toaccommodate different diameter pipes P. Pipes P are typically ofstandardized sequential diameters. If, for example, the blades 64 areeach sufficiently long to accommodate two sequential diameters of pipe Pand the large, intermediate and small outer diameter 73, 74 and 75 bladeholders 60 shown in FIGS. 3E, 3F and 3G, respectively, are available foruse, the same drive unit 10 can be used to face six different diametersof pipe P.

As seen in FIGS. 3A-3G, the weight of a blade holder 60 can be reducedby voids 76 through the disk 61. However, if the shaved ribbons S are tobe dispensed inside of the pipe P as by the blade holder 60 of FIG. 3C,it may necessary to close the voids 76 in some applications.

The Motor Assembly

Turning to FIG. 4, the motor assembly 80 has a motor 81 with a gearbox82 driving an output shaft 83 with a coupler 84 on its free end. In theembodiment of FIG. 4, a mounting frame 85 attached to the motor assembly80 by a bracket 86 has a mounting plug 87 adapted for engagement withthe socket 22 on the elongated frame 11 of the drive unit 10, as shownin FIG. 2A. The coupler 84 on the motor assembly output shaft 83 and theinput shaft coupler 31 of the drive unit 10 are spaced from the plug 87and the socket 22 to align the couplers 84 and 31 on a common centeraxis 88. Thus, the couplers 84 and 31 are automatically mechanicallyengaged for rotation in unison when the motor assembly 80 is mounted onthe drive unit 10 by telescoping the plug 87 into the socket 22. Adetent pin 89 inserted into aligned apertures 91 secures the telescopedplug 87 and socket 22 with the couplers 84 and 31 engaged.

The plug and socket components 87 and 22 could be switched to the driveunit 10 and motor assembly 80, respectively. In either configuration,the socket 22 and plug 87 are adapted for tool-free engagementpreventing horizontal and vertical displacement of the motor assembly 80in relation to the drive unit 10. Preferably, the telescoping socket 22and plug 87 are vertically aligned tubular members of squarecross-section.

The gearbox 82 is preferably a multi-speed gearbox operable at a speedselected to correspond to a cross-section of a pipe P being faced. Atwo-speed gearbox 82 can be set to low speed for larger and/or thickerpipe P and set to high speed for smaller and/or thinner pipe P. Thehorsepower required is governed in part by the speed of the blade 64,which is a function of RPM and pipe diameter, and wall thickness of thepipe P. The maximum required horsepower and blade holder RPM aregoverned by the largest and thickest pipe P. If the same RPM is used forsmaller and thinner pipe, the blade speed will be slower and will notdraw the full available horsepower. Using the high-speed setting forsmaller/thinner pipe P reduces facing time. Alternatively, the driveunit gearbox 32 may be adapted to provide the two-speed operation of thedrive unit output shaft 26 using a single speed motor assembly 83.

A pair of handles 92, each spaced from the motor 81 and gearbox 82 on acorresponding wing 93 of the motor assembly 80, extend on axes 94perpendicular to a diameter 95 of the motor 81 and gearbox 82 tofacilitate lifting and manipulating the motor assembly 80 into positionon the drive unit 10.

Assembly of the Facer

Looking at FIGS. 5 and 6, in assembling the facer F for use, the driveunit 10 is first mounted on the carriage guide rails R. This isaccomplished by lifting the drive unit 10 above and squared with thecarriage guide rails R, tilting the drive unit 10 so that the horizontalguide rail bracket 12 points toward one guide rail R, sliding it ontothat guide rail R until that guide rail R is fully seated in thehorizontal guide rail bracket 12, rocking the drive unit 10 on thatguide rail R toward the other guide rail R until the vertical guide railbracket 13 is fully seated on the other guide rail R and then swingingthe vertical guide rail bracket latch 19 to its closed condition.

Looking at FIGS. 5 and 7, with the blades 64 secured to their respectiveblade holders 60 at the desired angle for inside or outside dispersionof shaved ribbons S, the two blade holders 60 can each be lifted up andattached one at a time to the drive unit 10 by sliding them fully ontothe hex nuts on the drive unit output shaft 26 and closing the latchingassemblies 63 on the blade holders 60.

Looking at FIGS. 5 and 8, the motor assembly 80 is mounted on the driveunit 10 by raising the motor assembly 80 above the drive unit 10,aligning the plug 87 of the motor assembly 80 with the socket 22 of thedrive unit 10 and lowering the motor assembly 80 to fully engage theplug 87 in the socket 22, thereby simultaneously engaging the coupler 84of the motor assembly output shaft 83 with the coupler 31 of the driveunit input shaft 25 and aligning the apertures 91 in the plug 87 and thesocket 22. The detent pin 89 can then be inserted into the alignedapertures 91, completing the assembly of the facer F. Disassembly of thefacer F involves essentially a reversal of the steps of assembly.

The same facer F is seen in its assembled condition in FIG. 9A withlarge diameter blade holders 60, as seen in FIG. 3E, and in FIG. 9B withsmall diameter blade holders 60, as seen in FIG. 3G. The same drive unit10 is used at its widest spacing of brackets in FIG. 9A and at itsnarrowest spacing of brackets in FIG. 9B. The same motor assembly 80 isused, but would be set at its lowest speed in FIG. 9A and at its highestspeed in FIG. 9B. The facer F is seen in a horizontal orientation inFIGS. 9A and 9B and the blades 64 are angled for dispersing shavedribbons S into the pipe P as seen in FIG. 3C. If the facer F wererotated 90° to a vertical orientation, the upper blade 64 would beangled for dispersing shaved ribbons S inside of the pipe P as seen inFIG. 3C and the lower blade 64 would be angled for dispersing shavedribbons S outside of the pipe P as seen in FIG. 3D.

Thus, it is apparent that there has been provided, in accordance withthe invention, a facer that fully satisfies the objects, aims andadvantages set forth above. While the invention has been described inconjunction with specific embodiments thereof, it is evident that manyalternatives, modifications and variations will be apparent to thoseskilled in the art and in light of the foregoing description.Accordingly, it is intended to embrace all such alternatives,modifications and variations as fall within the spirit of the appendedclaims.

1.-9. (canceled)
 10. For mounting on the guide rails of a carriage of amachine used to fuse polyolefin pipe end-to-end, a facer drive unitcomprising: an elongated frame; two guide rail brackets, one on each endportion of said frame; two arrays of co-operable registries, each saidregistry corresponding to a respective one of said guide rail bracketsand configured to locate said guide rail brackets in any of multiplesymmetrically spaced relationships from a center of said frame; and twoindexing assemblies, one on each end portion of said frame, securingsaid guide rail brackets in said any of multiple symmetrically spacedrelationships at a spaced relationship closest to a distance between theguide rails.
 11. A facer drive unit according to claim 10, said twoguide rail brackets comprising: a U-shaped horizontal guide rail bracketengageable on one of the guide rails by lateral motion of said frame;and a U-shaped vertical guide rail bracket engageable on another of theguide rails by downward motion of said U-shaped vertical guide railbracket with said U-shaped horizontal guide rail bracket engaged on saidone of the guide rails.
 12. A facer drive unit according to claim 11further comprising a clamp mounted on said U-shaped horizontal guiderail bracket to constrain facer motion in a vertical plane and a clampmounted on said U-shaped vertical guide rail bracket to constrain facermotion in a horizontal plane.
 13. A facer drive unit according to claim11 further comprising a latch assembly mounted on said U-shaped verticalguide rail bracket to retain the facer on the guide rails.
 14. A facerdrive unit according to claim 10, each of said two arrays of co-operableregistries comprising: multiple apertures spaced longitudinally on saidelongated frame; and an aperture on its said respective one of saidguide rail brackets.
 15. A facer drive unit according to claim 14, eachof said index assemblies comprising spring pins.
 16. A facer drive unitaccording to claim 10 further comprising a linkage having an input shaftand an output shaft.
 17. A facer drive unit according to claim 16, saidlinkage further comprising a gearbox between said input shaft and outputshafts.
 18. A facer drive unit according to claim 16 further comprisingtwo adapters, one on each end of said linkage output shaft, each saidadapter enabling tool-free engagement on and rotation with said linkageoutput shaft of a respective blade holder with the blade holders inparallel.
 19. A facer drive unit according to claim 16 furthercomprising a mounting socket adapted for engagement with a frame of adrive motor assembly. 20.-30. (canceled)